人工胶结砂土力学特性的离散元模拟

采用离散单元法(DEM)对胶结砂土力学特性进行模拟。将基于室内试验测得的理想胶结颗粒接触力学响应引入到开发的二维离散元程序(NS2D)中,模拟胶结砂土颗粒间的胶结作用。对不同胶结强度和围压的胶结砂土进行平面应变双轴压缩试验模拟,并将模拟结果与Wang和Leung1]提供的人工胶结砂土的试验结果进行比较。最后对数值模拟中胶结试样的微观力学响应(接触力链、胶结点破坏率和位移场)进行分析。结果表明,离散元数值模拟能够有效地反映胶结砂土的主要力学特性,相比同一初始孔隙比的无胶结松散砂土,胶结砂土将具有更高的强度,应力-应变关系呈应变软化,体变为先剪缩后剪胀,且两者的差异随胶结强度的增大和围压的减小而越趋显著。此外,胶结砂土宏观力学响应(应力-应变关系和剪胀性)与其微观力学响应密切相关。

A DEM modelling of mechanical behaviour of artificially cemented sand

This paper presents a numerical investigation of cemented sand behaviours using the distinct element method(DEM).First,the test results of the contact behaviours between the idealized bonded granules were introduced in two-dimensional DEM code(NS2D) to simulate the bonding effect between particles in cemented sand.Second,a series of biaxial compression tests on cemented sand of different bonding strengths and confining pressures were carried out by the DEM simulations.Then,the DEM results were compared with...